FindJava¶

Finds the Java installation and determines its runtime tools and development components:

find_package(Java [<version>] [COMPONENTS <components>...] [...])

Added in version 3.10: Support for Java 9+ version parsing.

Components¶

This module supports optional components, which can be specified with the find_package() command:

find_package(Java [COMPONENTS <components>...])

Supported components include:

Runtime: Finds the Java Runtime Environment used to execute Java byte-compiled applications.
Development: Finds development tools (java, javac, javah, jar, and javadoc). Specifying this component also implies the Runtime component.
IdlJ: Added in version 3.4.

Finds the Interface Description Language (IDL) to Java compiler.
JarSigner: Added in version 3.4.

Finds the signer and verifier tool for Java Archive (JAR) files.

If no components are specified, the module searches for the Runtime component by default.

This module defines the following variables:

Java_FOUND: Added in version 3.3.

Boolean indicating whether (the requested version of) Java with all specified components was found.
Java_<component>_FOUND: Boolean indicating whether the <component> was found.
Java_VERSION: Version of Java found. This is set to: <major>[.<minor>[.<patch>[.<tweak>]]].
Java_VERSION_MAJOR: The major version of Java found.
Java_VERSION_MINOR: The minor version of Java found.
Java_VERSION_PATCH: The patch version of Java found.
Java_VERSION_TWEAK: The tweak version of Java found (part after the underscore character _).
Java_VERSION_STRING: Version of Java found, e.g., 1.6.0_12.

Note

Java_VERSION and Java_VERSION_STRING are not guaranteed to be identical. For example, some Java versions may return: Java_VERSION_STRING = 1.8.0_17 and Java_VERSION = 1.8.0.17.

Another example is the Java OEM, with Java_VERSION_STRING = 1.8.0-oem and Java_VERSION = 1.8.0.

The following cache variables may also be set:

Java_JAVA_EXECUTABLE: The full path to the Java runtime.
Java_JAVAC_EXECUTABLE: The full path to the Java compiler.
Java_JAVAH_EXECUTABLE: The full path to the Java header generator.
Java_JAVADOC_EXECUTABLE: The full path to the Java documentation generator.
Java_IDLJ_EXECUTABLE: Added in version 3.4.

The full path to the Java idl compiler.
Java_JAR_EXECUTABLE: The full path to the Java archiver.
Java_JARSIGNER_EXECUTABLE: Added in version 3.4.

The full path to the Java jar signer.

This module accepts the following variables:

JAVA_HOME: The caller can set this variable to specify the installation directory of Java explicitly.

Finding Java:

find_package(Java)

Finding Java with at least the specified minimum version:

find_package(Java 1.8)

Finding Java and making it required (if Java is not found, processing stops with an error message):

find_package(Java 1.8 REQUIRED)

Specifying the needed Java components to find:

find_package(Java COMPONENTS Development JarSigner)